I'd like to present you a little tinkering following my little trials in thermal imaging based on a camera I cobbled together from a second-hand camera core (see
https://www.eevblog.com/forum/thermal-imaging/my-first-little-diy-thermal-camera-project/ ):
So:
- A thermal camera (LWIR: 8-14 um) with a 15mm/1.0 Germanium lens + image capture by the small monocular associated with the camera, through a 2 francs six cents webcam (no Grabber at hand...)
and
- My usual IMX290 MM (CMOS) based system but equipped with a small 8mm/1.3 CCTV lens, instead of my big LOMO 160/2 lens. In order to be able to obtain in 2 parallel SC sessions simultaneously, by playing with the zooms, 2 images with about the same scale.
2 SharpCap (software dedicated to astro applications: live stacking, real time video...) sessions, and a window of one of the sessions made translucent by means of a small software found on the net "peek through", for example. and overlaying by hand a translucent window (the one in LWIR for example) on the main one (Vis/Nir).
Video tests (sorry for the second one, I'm in the field of the cam in my socks.... I just had the idea suddenly during the night... 😃 couldn't wait to try it!), and splash of cold and hot water on the floor, to visualize well the thermal side of the image....
As the superposition of the two videos is not very clear, we can see the difference between the Vis/Ir alone, in a part of the image, and the Vis/Ir + LWIR superposition in the rest of the image..... nice to realize the effects, highlighting the tehrmal gradients, the vegetation and some parts of the ground heated during the day.....
In short, a COTI or Fusion system (image intensifier (tubes) + thermal in military application) "poor man's" civilian hobbyist version... 😃 😃
COTI/Fusion systems have been around for 10-20 years, let's say in the military, and you can find them on the small FLIR/FLUKE/SEEK thermal cameras used in the civilian sector for thermal diagnostics in microelectronics, building, mechanics.....
https://www.google.com/search...The interest is to make the two technologies complementary on a single video stream in real time:
- In Vis/Nir in Night Vision, good resolution, but we are still dependent on a minimum of residual light (stars, moon, PL, etc...) and deep shadows are more difficult to scan, and for any immobile object visually blending into the landscape, even in intensified mode, it is sometimes difficult to detect,....
- In LWIR, if it's above absolute zero (-273.15°C) it's glowing... 😃, and between 8um-14um, we catch everything around us, in normal life, at room temperature, between 0°C and like 100°C without worrying (This is extremely and falsely simplified, (cf Planck's law, Stefan...) but just to say....), On the other hand, it works rather in low resolution compared to Vis/Nir applications in general, the visual renderings are confusing (we are very far from our "original/physiological" visual domain, the notions of emissivity take precedence over the usual reflectivity....), and then through certain "transparent" materials for our eyes as for ordinary glass or plexiglass, the thermal does not pass, these materials are opaque.... Water/mist (rain) can be a problem too....
In short, the idea is to merge the best of both spectral worlds to make "multi-spectral" night vision ....
here the manipulation, with the camera in piggy back on my usual device (with the LOMO here, but for my tests, it was replaced by the small CCTV 8mm/1.3 lens)
And the two test videos in a row....... captured with VLC... The fluidity is better in real life. to accelerate and walk around in it, to concentrate on for example the vegetal rendering heated the day before, and which jumps to the eyes at night, to compare to the Vis alone, or some parts of heated grounds or buildings, or air exhaust chimney outlets co....
Thank you for your reading patience!!!
to be continued! Lot of space for improvement: managing parallaxe for close scenary, adjusting contrast and gain for both camera (SC is good for that), adding a touch of color for the translucent window for clarifying the image in general....
Regards.
Lambda